Suction roll in particular for a paper web dryer

Abstract

A suction roll (1), in particular for a paper web dryer, comprising a perforated roll jacket (2), with at least one non-rotatable hollow shaft (3) which communicates with the interior of the suction roll via openings (7, 7') and at least one closing member (9) displaceable in the axial direction for separating off at least one peripheral region of the suction roll. The at least one, in particular disc-shaped dividing wall (5) is located in the suction roll interior and has at least one, preferably central opening (22). It can be of benefit when the dividing wall (5) corotates with the roll and/or when the at least one closing member (9) has the form of a hollow cylinder. Further, if the non-rotatable hollow shaft (3) is designed to be axially displaceable, it can be used to control the size of the opening (22) in the dividing wall (5).

What is claimed is: 
     
       1. Suction roll for a paper web dryer, comprising a perforated roll jacket, at least one non-rotatable hollow shaft of circular cross-section communicating with an interior of the suction roll via openings, at least one closure member for partitioning off at least-one edge region of the suction roll and being displaceable in the axial direction, and at least one disk-shaped, dividing wall comprising at least one central opening located in the interior of the suction roll. 
     
     
       2. Suction roll as set forth in claim 1, wherein the dividing wall corotates with the roll. 
     
     
       3. Suction roll as set forth in claim 1, wherein the at least one closure member is a hollow cylinder. 
     
     
       4. Suction roll as set forth in claim 3, wherein the hollow cylinder is displaceably arranged inside the hollow shaft. 
     
     
       5. Suction roll as set forth in claim 3, wherein the hollow cylinder has a closed cover at least at an end facing away from a point of suction out of the suction roll. 
     
     
       6. Suction roll as set forth in claim 1, including a fixed hollow shaft arranged in a central region of the suction roll and having openings cross-sections of which are controllable with the at least one closure member displaceable in the axial direction. 
     
     
       7. Suction roll as set forth in claim 2, wherein the hollow closure member is displaceable in the axial direction and is adapted to close the central opening of the corotating dividing wall. 
     
     
       8. Suction roll as set forth in claim 1, wherein the non-rotatable hollow shaft is cylindrical and of constant diameter at least along the interior of the suction roll and the closure member is disposed in the hollow shaft. 
     
     
       9. Suction roll for a paper web dryer comprising a perforated roll jacket having at least one non-rotatable hollow shaft of circular cross-section which communicates with an interior of a suction roll via openings, at least one closure member for partitioning off at least one edge region of the suction roll, at least one disk-shaped dividing wall in the interior of the suction roll which corotates with the roll and which comprises at least one central opening, the non-rotatable hollow shaft being constructed to be axially displaceable and serving as the closure member controlling a through flow cross-section of the central opening in the dividing wall. 
     
     
       10. Suction roll as set forth in claim 9, wherein the hollow shaft is closed at its end remote from a point of suction. 
     
     
       11. Suction roll as set forth in claim 10, wherein the hollow shaft in its end position closes the central opening in the corotating dividing wall. 
     
     
       12. Suction roll as set forth in claim 9, wherein the non-rotatable hollow shaft constructed as a closure member displaceable in the axial direction is cylindrical and of constant diameter at least along the suction roll. 
     
     
       13. Suction roll as set forth in claim 1, wherein two edge regions can be partitioned off and are adapted to be connected to suction apparatus, and including corotating dividing walls having openings and closure members therefor which are displaceable in the axial direction. 
     
     
       14. Suction roll as set forth in claim 9, wherein two edge regions can be partitioned off and are adapted to be connected to suction apparatus, and including corotating dividing walls having openings and closure members therefor which are displaceable in the axial direction. 
     
     
       15. Suction roll as set forth in claim 1, including a displacing device for the closure members connected to a central control for the paper web dryer. 
     
     
       16. Suction roll as set forth in claim 9, including a central control for the paper web dryer and a displacing device for the closure member connected to the central control. 
     
     
       17. Suction roll as set forth in claim 1, including a central control for the paper web dryer and a pressure measurement point at the hollow shaft which is axially displaceable, the pressure measurement point being connected to the central control. 
     
     
       18. Suction roll as set forth in claim 9, including a central control for the paper web dryer and a pressure measurement point at the hollow shaft which is axially displaceable, the pressure measurement point being connected to the central control. 
     
     
       19. Suction roll as set forth in claim 1, including vanes mounted on a circumference of the hollow shaft. 
     
     
       20. Suction roll as set forth in claim 9, including vanes mounted on a circumference of the hollow shaft.